Causes insomnia Essay Example for Free

Causes insomnia Essay The evolutionary theory can be directly linked to Darwins theory of survival of the fittest as any properties we have now are a result of what has been useful in the past therefore we sleep as it has been useful for our survival or it was at one time. Conservation was an idea that the theorist Webb came up with he suggested that those animals that slept more were more likely to survive such as hedgehogs. Conservation is where the body slows down the metabolism and heart rate as no food is being consumed and no energy is being used up as the animal is not moving about. Webbs theory is linked to hibernation mostly as his theory is more suggesting the likelihood of surviving due to sleeping. By looking at both theories I can now come to the conclusion that the restoration theory is more logical in its use of energy as it suggests that the more energy you use up in the day the more you look forward to going to bed to restore tissue and save energy. It also suggests that even if you dont fully exert yourself in a day it doesnt mean that your not going to sleep for long and this can be fully evident in teenagers as even if they do or dont exert themselves they still sleep a lot more as there bodies are developing and they need more sleep then the rest to gain in energy and also to give there bodies a time to relax as there bodies will be constantly secreting hormones. The cause and effect of insomnia still arent clear as the Pineal gland in the brain converts the neurotransmitter serotonin into the hormone melatonin. Melatonin is released into the blood stream and causes rhythmic changes around the body although the need for sleep is not affected by light. Melatonin plays a role in the co-ordination of the sleep wake cycle. So as sleep isnt affected by light then the cause of insomnia cant be known as you cant determine what effects the body that causes insomnia. REM sleep involves an increase in energy expenditure and blood flow which inhibits protein synthesis on the other hand it is known that amino acids are not stored by the body and last in the body for bout 4 hours after a meal. This means that protein synthesis maybe stopped half way through sleep because the amino acids have run out. Also people will sleep more after stress and it is known to improve moods which again can be explained by the fact that with NREM sleep occurring during slow wave so enables the body to repair itself and there is an increase in secretion of growth hormones. By looking at the evolutionary theory I can also conclude that the arguments presented for the evolutionary theory contradict themselves as some suggest that some animals sleep less to keep a vigil while others suggest that animals sleep longer to keep motionless thus staying away from harm. Also it is clear to see that animals such as lions do sleep longer as they are at less of a risk from being hunted so dont need that much sleep and animals like cattle need very little sleep and this puts them in danger of being hunted.